$-10tu - 6tv - 9t + 5 = -6u - 10$ Solve for $t$.
Explanation: Combine constant terms on the right. $-10tu - 6tv - 9t + {5} = -6u - {10}$ $-10tu - 6tv - 9t = -6u - {15}$ Notice that all the terms on the left-hand side of the equation have $t$ in them. $-10{t}u - 6{t}v - 9{t} = -6u - 15$ Factor out the $t$ ${t} \cdot \left( -10u - 6v - 9 \right) = -6u - 15$ Isolate the $t$ $t \cdot \left( -{10u - 6v - 9} \right) = -6u - 15$ $t = \dfrac{ -6u - 15 }{ -{10u - 6v - 9} }$ We can simplify this by multiplying the top and bottom by $-1$. $t= \dfrac{6u + 15}{10u + 6v + 9}$